(1) Field of the Invention
A baffled gun muzzle break capable of diverting exhaust gases of a fired underwater gun before sabot separation of a projectile.
(2) Description of the Prior Art
It is known in the art that underwater gun systems may be utilized as anti-mine and anti-torpedo devices. A basic underwater gun system includes underwater projectiles, an underwater gun, a ship-mounted turret, a targeting system, and a combat control system.
In operation of the underwater gun system, undersea targets (such as mines and torpedoes) are identified and localized with the targeting system. Based on signaling from the targeting system, the combat control system provides the commands to direct the ship-mounted turret to aim the underwater gun at the target. When directed, the underwater gun shoots the underwater projectiles in which the projectiles are specially designed for neutralization of undersea targets at a relatively long range (approximately 200 m).
In regard to the gun itself, guns with high muzzle velocities cannot be fired with water in their barrel. Firing a water-filled barrel results in very high breach pressures as the ignited propellant charge attempts to force the water out of the barrel. A likely result of high breach pressures is a material failure of the barrel.
In order to obtain the desired ranges, the projectile must travel through the water in a vapor cavity. A truncated cone is the optimum projectile shape to maximize the projectile mass that will maintain the vapor cavity. The truncated cone shape requires that the projectile be enclosed in a sabot within the barrel. Sabots are generally comprised of two or more petals in which the sabots have a cup on a leading edge in which the cup is designed to deflect and separate the petals from the projectile due to greater wind or other resistance on the petals relative to projectile as the round travels through the ambient gas medium.
For guns using sabots, a muzzle break must be mounted on the end of the barrel to allow the sabot to separate from the projectile. However, an exhaust gas pressure wave, occurring during firing from the ignited propellant charge, travels though the chamber at a rate equal to or greater than the round thereby inhibiting the sabot separation. For sabots fired into ambient air, this is generally not a problem since the exhaust gases are easily dissipated allowing the sabots to separate well. A problem occurs when rounds are fired into a confined muzzle break on the end of an underwater gun with the exhaust gas wave traveling though the sabot separation chamber at a rate equal to or greater than the round.
Since the exhaust gases cannot be readily dissipated, the fired round experiences a greatly reduced velocity through the gas and the sabot petals do not separate as quickly. As such, it is important that a significant quantity of the exhaust gases be diverted at the beginning of the sabot separation chamber to improve the separation process. However, the diversion of the exhaust gases must be done while still maintaining a water seal on the chamber prior to firing of the gun. As such, a muzzle break for the underwater gun must be designed to exhaust gases at the beginning of the separation stage while still maintaining a water seal on the chamber until the projectile exits the gun.
In Curtis et al. (U.S. Pat. No. 5,966,858), a baffled muzzle break and seal system for operation of a submerged gun is provided. Specifically, the cited reference provides baffle assembly within a gun chamber in which the baffle assembly deflects the propellant gasses produced by operation of the gun to an annular chamber. A pressurized air input prevents the entry of water when a water seal of the gun is opened to allow passage of a projectile. A valve gas exhaust provides a means for removing propellant gases from the chamber.
An improvement to the muzzle break of the cited reference as well as any other muzzles breaks for underwater guns that are known in the art would be a simpler constructed muzzle break with the ability to divert exhaust gases at the beginning of the separation stage of a sabot projectile while still maintaining a water seal on the separation chamber of the gun. Instead of reliance on a valve gas exhaust to remove exhaust gases and an increased size of the underwater gun when an annular chamber is part of the gun, a simpler muzzle break should be able divert exhaust gases immediately and efficiently while minimizing the complexity of the muzzle break.